A well-implemented Tron for iPhone is cool enough on its own, but most impressive is this version's incredibly cool approach to multiplayer: a vertical splitscreen puts both players' hands in the game at once. Updated

Credit goes to Japanese devs Pankaku, who have several other nice-looking music apps. The game's called Light Bike, and it's not in the store yet, but it will be soon-a free version is single-player only, and the multiplayer version (which can also play over wi-fi with up to four players-two on each phone) will cost a few bucks. [YouTube]